HTB——vault

unsigned __int64 sub_C220()
{
  __int64 (__fastcall ***v0)(); // rdi
  char v2; // [rsp+7h] [rbp-239h]
  unsigned __int8 v3; // [rsp+13h] [rbp-22Dh]
  int i; // [rsp+14h] [rbp-22Ch]
  char v5; // [rsp+1Bh] [rbp-225h]
  char v6; // [rsp+2Fh] [rbp-211h] BYREF
  __int64 v7[66]; // [rsp+30h] [rbp-210h] BYREF

  v7[65] = __readfsqword(0x28u);
  std::ifstream::basic_ifstream(v7, "flag.txt", 8LL);	// 读取当前目录下'flag.txt'中的字符
  if ( (std::ifstream::is_open(v7) & 1) == 0 )
  {
    std::operator<<>(&std::cout, "Could not find credentialsn");
    exit(-1);
  }
  v5 = 1;
  for ( i = 0; ; ++i )
  {
    v2 = 0;
    if ( (unsigned __int64)i < 25 )  // flag长度为25
      v2 = std::ios::good((char *)v7 + *(_QWORD *)(v7[0] - 24));
    if ( (v2 & 1) == 0 )
      break;
    std::istream::get((std::istream *)v7, &v6);
    v0 = off_17880[byte_E090[i]];
    v3 = ((__int64 (__fastcall *)(__int64 (__fastcall ***)()))**v0)(v0);
    if ( v6 != v3 )
      v5 = 0;
  }
  if ( (v5 & 1) != 0 )
    std::operator<<>(&std::cout, "Credentials Accepted! Vault Unlocking...n");
  else
    std::operator<<>(&std::cout, "Incorrect Credentials - Anti Intruder Sequence Activated...n");
  std::ifstream::~ifstream(v7);
  return __readfsqword(0x28u);
}

在当前目录下创建一个txt文件，输入25个任意字符，然后gdb调试

动态编译先获取下基地址

set stop-on-solib-events 1
r
vmmap
q

获取基地址后，重新进入gdb调试，直接在比较flag处下断

b *(0x0000555555554000 + 0xC3A1)
r

此时RAX中存放的是flag.txt中的字符，RCX中存放的是真正的flag

用c命令多次执行获取flag的值

HTB{vt4bl3s_4r3_c00l_huh}